I am new to brewing and I was wondering if anyone has any experience with
brewing beer in wooden barrels? If so, what are the considerations eg.
hygiene, cleaning, modifications, etc? Also does brewing in wood make the
beer taste better?

I am fairly new to the whole brewing experience, but I would probably
be inclined to say not to use a wooden barrel for primary fermentation.

This is going to be a lot harder to clean than plastic or glass due to
the number of gaps in the wood! My main theory is based on the idea
that you are discouraged from using a wooden spoon for stiring your
wort.

I may be wrong but I would say don't do it! You would probably be okay
in secondary since there will be more alcohol and this will be more
tolerant to bacteria. Don't take my word for it!

Despite what everybody says, you could always take the option of try it
to see what happens. You never know you might like the results. I would
only do this if you are willing to ruin an entire batch though!!! Could
be worth the gamble :D

Don't do it! Of course you could do it and find out for yourself. People
used to do it, otherwise we wouldn't have the "Beer Barrel Polka". People
also used to brew in big crocks as well. I wonder if that's where the
expression "I'm crocked" came from? The problem with Crocks and Barrels is
like the previous person stated. Too many places for wild yeastie beasties
to hide. They are difficult to impossible to clean thoroughly. You can buy
oak chips from brewing supply houses that will give the same effect as
brewing in a barrel. Plastic is good, glass is better.

Others can maybe chime in with more info... but the other posters are
probably right... wood is hard to clean and probably impossible for
homebrewers to sanitize. Beer that is made in wood will probably turn
out with a sour taste (on purpose) because of the bacteria that can't
really be removed from it. That was likely the standard taste of beer
years ago - and there are still some specialty beers today brewed in wood.

Also, beer can be served in wooden kegs but not fermented in them.
A short length of time in the wood wouldn't create much/any taste.
Further, most of those barrels from the past were coated on the inside
with "pitch" (tar) so there wouldn't be any wood taste anyway.

If you want a wood taste (oak, etc), then some folks use wood chips.
They steam the chips for a period of time to sanitize them and then
put the chips into the beer during fermentation/lagering.

I think it would be very hard to actually brew the beer in the wooden
barrel, as it would keep catching fire while you were brewing.

Now if you are asking if you can FERMENT the beer in a wooden cask,
the answer is yes - but I don't recommend it. It will be extremely
hard to properly sanitize it. Whether or not it tastes better is up
to your individual tastes as well. I've had a pale ale that was cask
aged and tapped straight from the cask. I found it somewhat flat and
the taste not very much to my liking. To each their own, however.